Diimide Photoluminescent Materials Containing a Spin-Forbidden System, Preparation Methods Thereof, and Applications

Abstract

The present invention discloses a diimide photoluminescent material containing a spin-forbidden system, its preparation method and applications. The diimide photoluminescent material has a structure shown by any one of the following formulas: The diimide photoluminescent material containing a spin-forbidden system provided by the present invention has the characteristics of realizing fluorescence, delayed fluorescence and room-temperature phosphorescence triple emission, with a phosphorescence lifetime of up to hundreds of milliseconds and a delayed fluorescence of up to hundreds of microseconds, and has great application prospects in the field of organic photoluminescence.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic photoluminescence, and particularly relates to a diimide photoluminescent material containing a spin-forbidden system, its preparation method and application. Background Art

[0002] In recent years, with the development of photoluminescent materials, delayed fluorescence and phosphorescent materials have irreplaceable positions and performance advantages in the field of photoluminescence. Pure organic room temperature phosphorescent materials have attracted much attention in the fields of anti-counterfeiting, bioimaging and organic optoelectronics because of their low cost, adjustable functions, low cytotoxicity, good processability, etc. In addition, fluorescence, delayed fluorescence and room temperature phosphorescence triple emission materials have a multi-layer encryption effect in anti-counterfeiting, so they have attracted great attention and research interest of researchers. The fluorescence lifetime of traditional fluorescent materials is only a few nanoseconds, while the lifetime of delayed fluorescence materials can reach the microsecond level, which is beneficial to improving their applications in the field of organic photoluminescence. At present, most phosphorescent and delayed fluorescence materials achieve photoluminescence by doping metal ions, but the metal complexes that often promote luminescence are precious metals, which are not only expensive but also have biological toxicity, seriously hindering the development of fluorescent phosphorescent materials in bioimaging and organic optoelectronics fields; moreover, the short lifetime and low quantum efficiency of monomer phosphorescence and delayed fluorescence of the existing imide structure seriously limit their development. Therefore, there is an urgent need for a pure organic, low-toxic material with ultra-long room temperature phosphorescence, fluorescence and delayed fluorescence lifetimes and high quantum efficiency. Summary of the Invention

[0003] The main object of the present invention is to provide a diimide photoluminescent material containing a spin-forbidden system, its preparation method and application, so as to overcome the deficiencies of the prior art.

[0004] To achieve the foregoing invention object, the technical solutions adopted by the present invention include:

[0005] The embodiment of the present invention provides a diimide photoluminescent material containing a spin-forbidden system, and the diimide photoluminescent material has a structure shown in any one of formulas (I)-(IV):

[0006]

[0007] Wherein, R independently selects any one or a combination of two or more of the structures shown in the following formula:

[0008]

[0009] Wherein, * is the connection point of the group.

[0010] The embodiment of the present invention also provides a preparation method of the foregoing diimide photoluminescent material containing a spin-forbidden system, which includes:

[0011] The first mixed reaction system containing a halogenated phthalic anhydride, an amine monomer, and a first solvent is subjected to an imide reaction at 110°C to 120°C for 12 to 24 hours to obtain a halogenated phthalimide intermediate compound;

[0012] In addition, the second mixed system containing the halogenated phthalimide intermediate compound, norbornadiene, an inorganic base, a catalyst, and a second solvent is reacted at 130°C to 150°C for 72 - 120 hours to obtain a diimide photoluminescent material containing a spin-forbidden system.

[0013] An embodiment of the present invention also provides the use of the aforementioned diimide photoluminescent material containing a spin-forbidden system in the preparation of anti-counterfeiting labels.

[0014] An embodiment of the present invention also provides the use of the aforementioned diimide photoluminescent material containing a spin-forbidden system in biological imaging or organic photovoltaic optoelectronics.

[0015] An embodiment of the present invention also provides an organic material with fluorescence, delayed fluorescence, and room temperature phosphorescence triple emission, which at least includes the aforementioned diimide photoluminescent material containing a spin-forbidden system.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) The photoluminescent material of the present invention belongs to organic imide small molecules. The preparation method is simple, the raw materials are easily available, the price is cheap, the reaction conditions are mild and biocompatible, and it can be applied to biological imaging;

[0018] (2) By fine-tuning the structure, the present invention can realize the regulation of the emission color and emission lifetime of fluorescence, delayed fluorescence, and room temperature phosphorescence;

[0019] (3) The room temperature phosphorescence of the photoluminescent material in the present invention has a long phosphorescence lifetime and quantum yield, which is greatly improved compared with the previous pure organic room temperature phosphorescent materials;

[0020] (4) The photoluminescent material of the present invention can realize the photoluminescent phenomenon of fluorescence, delayed fluorescence, and room temperature phosphorescence triple emission, and can realize multiple encryption of the material, and has great application prospects in the preparation of anti-counterfeiting labels. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is the 1H NMR spectrum of the imide photoluminescent material in Example 1 of the present invention;

[0023] Figure 2 is the ultraviolet absorption spectrum of the imide photoluminescent material in Example 1 of the present invention;

[0024] Figure 3 is the difference diagram of the fluorescence spectral intensities of the imide photoluminescent material in Example 1 of the present invention at different excitation wavelengths;

[0025] Figure 4 is the fluorescence spectrum diagram of the imide photoluminescent material in Example 1 of the present invention with the emission intensity normalized at different excitation wavelengths;

[0026] Figure 5 is the fluorescence, delayed fluorescence and phosphorescence spectrum diagram of the imide photoluminescent material in Example 1 of the present invention;

[0027] Figure 6 is the phosphorescence lifetime spectrum diagram of the imide photoluminescent material in Example 1 of the present invention at 590 nm under the light wavelength of 365 nm;

[0028] Figure 7 is the appearance diagram of the imide photoluminescent material in Example 1 of the present invention before and after irradiation with 365 nm UV light and the phosphorescence emission; Detailed implementation manners

[0029] In view of the defects of the prior art, the inventors of this case have proposed the technical solution of the present invention through long-term research and a large number of practices. It mainly uses halogenated phthalic anhydride, norbornadiene and amine derivatives as the initial raw materials for the reaction. First, halogenated phthalic anhydride reacts with amine derivatives in acetic acid solution to synthesize a halogenated phthalimide intermediate compound. After washing with brine, extraction with dichloromethane, rotary evaporation and drying, column chromatography purification, sublimation and other operations, the halogenated phthalimide intermediate compound is purified; then under alkaline conditions, through the palladium-catalyzed dibenzocyclobutane norbornane-arene cyclization (CANAL) reaction, the halogenated phthalimide and norbornadiene are synthesized into an imide photoluminescent triple-emission material containing a spin-forbidden system under the catalysis of a catalyst. The reactants are subjected to operations such as washing with brine, extraction with dichloromethane, rotary evaporation and concentration, column chromatography purification, sublimation, etc., to obtain an imide photoluminescent triple-emission material containing a spin-forbidden system.

[0030] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Specifically, as an aspect of the technical solution of the present invention, a diimide photoluminescent material containing a spin-forbidden system has a structure shown in any one of Formula (I) - Formula (IV):

[0032]

[0033] Wherein, R independently selects any one or a combination of two or more of the structures shown in the following formula:

[0034]

[0035] Wherein, * is the connection point of the group.

[0036] Another aspect of the embodiments of the present invention also provides a preparation method of the aforementioned diimide photoluminescent material containing a spin-forbidden system, which includes:

[0037] Carrying out an imide reaction on a first mixed reaction system containing a halogenated phthalic anhydride, an amine monomer, and a first solvent at 110°C to 120°C for 12 to 24 hours to obtain a halogenated phthalimide intermediate compound;

[0038] And reacting a second mixed system containing the halogenated phthalimide intermediate compound, norbornadiene, an inorganic base, a catalyst, and a second solvent at 130°C to 150°C for 72 - 120 hours to obtain a diimide photoluminescent material containing a spin-forbidden system.

[0039] Specifically, the synthesis of the diimide photoluminescent material containing a spin-forbidden system is as follows in the example process:

[0040]

[0041] x is one of Br, Cl, and I, and preferably Br.

[0042] Wherein, R independently selects any one or several of the following structures:

[0043]

[0044] Wherein, * is the connection point of the group.

[0045] In some preferred embodiments, the halogenated phthalic anhydride includes any one or a combination of two or more of brominated phthalic anhydride, chlorinated phthalic anhydride, and iodinated phthalic anhydride, and is not limited thereto.

[0046] Further, the halogenated phthalic anhydride is brominated phthalic anhydride.

[0047] In some preferred embodiments, the amine monomer is selected from any one or a combination of two or more of the structures represented by the following formula:

[0048]

[0049] In some preferred embodiments, the first solvent includes any one or a combination of two or more of acetic acid, formic acid, and propionic acid, and is not limited thereto.

[0050] Further, the first solvent is acetic acid.

[0051] In some preferred embodiments, the inorganic base includes any one or a combination of two or more of potassium carbonate, sodium carbonate, cesium carbonate, calcium carbonate, and magnesium carbonate, and is not limited thereto.

[0052] Further, the inorganic base is cesium carbonate.

[0053] In some preferred embodiments, the catalyst includes any one or a combination of two or more of palladium acetate, tris(dibenzylideneacetone)dipalladium, and tetrakis(triphenylphosphine)palladium and triphenylphosphine.

[0054] Further, the catalyst includes palladium acetate and triphenylphosphine, and is not limited thereto.

[0055] In some preferred embodiments, the second solvent includes toluene and / or dioxane, and is not limited thereto.

[0056] Further, the second solvent is toluene.

[0057] In some preferred embodiments, the molar ratio of the halogenated phthalic anhydride to the amine monomer is 1:1 to 1:1.2.

[0058] In some preferred embodiments, the mass ratio of the halogenated phthalic anhydride to the first solvent is 1:10 to 1:20.

[0059] In some preferred embodiments, the mass ratio of the halogenated phthalimide intermediate compound to the second solvent is 1:30 to 1:50.

[0060] In some preferred embodiments, the molar ratio of the halogenated phthalimide intermediate compound to norbornadiene is 2.2:1 to 2.1:1.

[0061] In some preferred embodiments, the molar ratio of the norbornadiene to the inorganic base is 1:2 to 1:2.2.

[0062] In some preferred embodiments, the ratio of the norbornadiene to the catalyst is 1:0.05:0.2 to 1:0.1:0.4.

[0063] In some preferred embodiments, the reaction time of the imide reaction is 16 to 24 h.

[0064] In some preferred embodiments, the reaction temperature of the imide reaction is 120 °C to 150 °C.

[0065] In some preferred embodiments, the reaction temperature of the second mixed system is 130 °C to 150 °C.

[0066] In some preferred embodiments, the preparation method further includes: after the imide reaction is completed, adding brine to quench the first mixed system, and then performing extraction, concentration, and purification to obtain the halogenated phthalimide intermediate compound.

[0067] In some preferred embodiments, the preparation method further includes: adding brine to quench after the second mixed reaction system is completed, and then performing extraction, concentration, and purification to obtain the diimide photoluminescent material containing a spin-forbidden system.

[0068] In some more specific embodiments, the preparation method includes: after the reaction is completed, performing extraction, liquid separation, washing, column chromatography separation, rotary evaporation, drying, recrystallization, and other treatments on the reaction product.

[0069] In some more specific embodiments, the preparation method of the diimide photoluminescent material containing a spin-forbidden system includes:

[0070] Dissolving the halogenated phthalic anhydride in a first solvent, then slowly adding an amine monomer to form a first mixed system, and performing an imide reaction for 12 to 24 h under reflux at 110 °C to 120 °C to obtain a halogenated phthalimide intermediate compound; after the first mixed system at the end of the reaction is continuously washed with brine, extracted with dichloromethane, the organic phase is collected, rotary evaporated and dried, and then purified by column chromatography separation, recrystallization, sublimation drying, etc. to obtain the halogenated phthalimide intermediate compound;

[0071] Moreover, a second mixed system containing the halo-phthalimide intermediate compound, norbornadiene, inorganic base, catalyst and second solvent is reacted at 130°C to 150°C for 72 - 120 h to obtain a diimide photoluminescent material containing a spin-forbidden system. After the reaction is completed, the second mixed system is continuously washed with brine, extracted with dichloromethane, the organic phase is collected, rotary evaporated to dryness, and then subjected to treatments such as column chromatography separation and purification, recrystallization, and sublimation drying to obtain the diimide photoluminescent material containing a spin-forbidden system.

[0072] In some more specific embodiments, the method for preparing the diimide photoluminescent material containing a spin-forbidden system includes:

[0073] S1. Prepare intermediate Y (i.e., the aforementioned "halo-phthalimide intermediate compound"):

[0074]

[0075] Wherein, R is independently selected from any one or several of the following structures:

[0076]

[0077] Wherein, * is the connection point of the group;

[0078] S2. Use intermediate Y to obtain a diimide photoluminescent material through a palladium-catalyzed dibenzocyclobutane norbornane-arene cyclization (CANAL) reaction:

[0079]

[0080] Wherein, R is independently selected from any one or several of the following structures:

[0081]

[0082] Wherein, * is the connection point of the group.

[0083] The diimide photoluminescent material containing a spin-forbidden system in the present invention has the characteristics of enabling fluorescence, delayed fluorescence, and room-temperature phosphorescence triple emission. The phosphorescence lifetime can reach up to several hundred milliseconds at most, and the delayed fluorescence reaches several hundred microseconds. It has great application prospects in the field of organic photoluminescence.

[0084] Another aspect of the embodiments of the present invention also provides the use of the aforementioned diimide photoluminescent material containing a spin-forbidden system in the preparation of anti-counterfeiting labels.

[0085] The diimide photoluminescent material having triple emission at room temperature in the present invention multiplexes and encrypts information and has great application value in anti-counterfeiting labels.

[0086] Another aspect of the embodiments of the present invention further provides the use of the aforementioned imide photoluminescent material containing a spin-forbidden system in biological imaging or organic photovoltaic optoelectronics.

[0087] Another aspect of the embodiments of the present invention further provides an organic material with fluorescence, delayed fluorescence, and room temperature phosphorescence triple emission, which at least includes the aforementioned imide photoluminescent material containing a spin-forbidden system.

[0088] The technical solutions of the present invention will be further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. These embodiments are implemented on the premise of the technical solutions of the invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0089] In the following embodiments, the experimental materials used can be obtained from conventional biochemical reagent companies without special instructions.

[0090] Example 1

[0091] The structural formula of compound DI-1 is as follows:

[0092]

[0093] The synthesis steps of compound DI-1 are as follows:

[0094] Dissolve 3-bromophthalic anhydride (10.22 g) in solvent acetic acid (50 mL), and then slowly dropwise add aqueous methylamine solution (5.60 g) to form a mixed system. Carry out the imide reaction at 120 °C for reflux for 12 h. Pour the reaction system into deionized water to precipitate an insoluble precipitate. Filter the precipitate, wash it with a large amount of deionized water to remove acetic acid and methylamine, and dry it at 120 °C under vacuum. Obtain 3-bromophthalimide compound (10.10 g, yield 93.5%);

[0095] And, a mixed system containing the 3-bromophthalimide compound (3.48 g), norbornadiene (0.65 g), cesium carbonate (4.56 g), triphenylphosphine (0.73 g), palladium acetate (0.16 g) and solvent dioxane (100 mL) is reacted at 130 °C for 72 h. After the reaction is completed, wash the reaction system with aqueous sodium chloride solution, then extract the organic phase with dichloromethane, rotary evaporate, dry, and recrystallize to obtain an imide photoluminescent material containing a spin-forbidden system (2.15 g, yield 74.7%).

[0096] The synthesis route of compound DI-1 is shown as follows:

[0097]

[0098] The proton nuclear magnetic resonance spectrum of the imide-based photoluminescent material in this example is as Figure 1 shown; the ultraviolet absorption spectrum is as Figure 2 shown; the difference diagram of the fluorescence spectral intensities of the imide-based photoluminescent material at different excitation wavelengths is as Figure 3 shown; the normalized fluorescence spectrum diagram of the imide-based photoluminescent material at different excitation wavelengths is as Figure 4 shown; the fluorescence, delayed fluorescence, and phosphorescence spectrum diagrams of the imide-based photoluminescent material are as Figure 5 shown; the phosphorescence lifetime spectrum diagram of the imide-based photoluminescent material at 590 nm at a light wavelength of 365 nm is as Figure 6 shown; the appearance diagrams of the imide-based photoluminescent material before and after irradiation with 365 nm UV light and its phosphorescence emission are as Figure 7 shown.

[0099] The properties of the compound DI-1 prepared in this example and those of the existing pure organic room-temperature phosphorescent materials are shown in Table 1:

[0100] Table 1 Properties of Compound DI-1 and Existing Pure Organic Room-Temperature Phosphorescent Materials

[0101] Name Phosphorescence Lifetime / (ms) Quantum Yield (%) Material DI-1 of the Present Invention 379.1 ms 6.4 BDBT 103.7 ms 2.3 FBDBT 106.7 ms 6.5 CIBDBT 123.4 ms 7.2 BrBDBT 103.8 ms 6.8 ODFRCZ 345.5 ms -

[0102]

[0103] Example 2

[0104] The structural formula of compound DI-2 is as follows:

[0105]

[0106] The synthesis steps of compound DI-2 are as follows:

[0107] Dissolve 3-bromophthalic anhydride (2.27 g) in the solvent acetic acid (20 mL), then slowly add aniline (1.86 g) to form a mixed system and carry out an imide reaction at 120 °C under reflux for 18 h. Pour the reaction system into deionized water for washing, extract with dichloromethane, rotary evaporate to dryness, purify by column chromatography, and dry at 120 °C under vacuum. Obtain 3-bromophthalimide compound (2.62 g, yield 86.8%);

[0108] And, a mixed system containing the 3-bromophthalimide compound (1.26 g), norbornadiene (0.18 g), cesium carbonate (0.65 g), triphenylphosphine (0.21 g), palladium acetate (0.16 g) and the solvent dioxane (50 mL) was reacted at 130 °C for 120 h. After the reaction was completed, the reaction system was washed with an aqueous sodium chloride solution, and then the organic phase was extracted with dichloromethane, rotary evaporated, dried, and recrystallized to obtain a diimide photoluminescent material containing a spin-forbidden system (0.71 g, yield 66.4%).

[0109] The synthetic route of compound DI-2 is as follows:

[0110]

[0111] Example 3

[0112] The structural formula of compound DI-3 is as follows:

[0113]

[0114] The synthesis steps of compound DI-3 are as follows:

[0115] Dissolve 3-bromophthalic anhydride (1.14 g) in the solvent acetic acid (11.5 mL), and then slowly add p-fluoroaniline (0.67 g) dropwise to form a mixed system. The imide reaction was carried out under reflux at 110 °C for 24 h. The reaction system was poured into deionized water for washing, extracted with dichloromethane, rotary evaporated and dried, purified by column chromatography, and dried at 120 °C under vacuum. 3-Bromophthalimide compound (1.12 g, yield 70.4%) was obtained;

[0116] And, a mixed system containing the 3-bromophthalimide compound (1.05 g), norbornadiene (0.14 g), cesium carbonate (1.08 g), triphenylphosphine (0.08 g), palladium acetate (0.017 g) and the solvent dioxane (50 mL) was reacted at 130 °C for 120 h. After the reaction was completed, the reaction system was washed with an aqueous sodium chloride solution, and then the organic phase was extracted with dichloromethane, rotary evaporated, dried, and recrystallized to obtain a diimide photoluminescent material containing a spin-forbidden system (0.59 g, yield 69.0%).

[0117] The synthetic route of compound DI-3 is as follows:

[0118]

[0119] Example 4

[0120] The structural formula of compound DI-4 is as follows:

[0121]

[0122] The synthesis steps of compound DI-4 are as follows:

[0123] Dissolve 3-bromophthalic anhydride (1.14 g) in the solvent acetic acid (22.5 mL), then slowly add p-toluidine (0.54 g) dropwise to form a mixed system, and carry out an imide reaction at 120 °C under reflux for 12 h. Pour the reaction system into deionized water for washing, extract with dichloromethane, rotary evaporate to dryness, separate and purify by column chromatography, and dry at 130 °C under vacuum. Obtain 3-bromophthalimide compound (1.40 g, yield 88.6%);

[0124] And, make a mixed system containing the 3-bromophthalimide compound (1.32 g), norbornadiene (0.18 g), cesium carbonate (1.30 g), triphenylphosphine (0.21 g), palladium acetate (0.045 g) and the solvent dioxane (40 mL) react at 150 °C for 72 h. After the reaction is completed, wash the reaction system with an aqueous sodium chloride solution, then extract the organic phase with dichloromethane, rotary evaporate, dry, and recrystallize to obtain a diimide photoluminescent material containing a spin-forbidden system (0.86 g, yield 76.1%).

[0125] The synthesis route of compound DI-4 is as follows:

[0126]

[0127] Example 5

[0128] The structural formula of compound DI-5 is as follows:

[0129]

[0130] The synthesis steps of compound DI-5 are as follows:

[0131] Dissolve 3-bromophthalic anhydride (1.14 g) in the solvent acetic acid (17 mL), then slowly add p-trifluoromethylaniline (0.89 g) dropwise to form a mixed system, and carry out an imide reaction at 115 °C under reflux for 15 h. Pour the reaction system into deionized water for washing, extract with dichloromethane, rotary evaporate to dryness, separate and purify by column chromatography, and dry at 130 °C under vacuum. Obtain 3-bromophthalimide compound (1.59 g, yield 85.9%);

[0132] And, a mixed system containing the 3-bromophthalimide compound (1.19 g), norbornadiene (0.14 g), cesium carbonate (1.02 g), triphenylphosphine (0.15 g), palladium acetate (0.025 g) and the solvent dioxane (48 mL) was reacted at 140 °C for 96 h. After the reaction was completed, the reaction system was washed with an aqueous sodium chloride solution, and then the organic phase was extracted with dichloromethane, rotary evaporated, dried, and recrystallized to obtain a diimide photoluminescent material containing a spin-forbidden system (0.69 g, yield 69.0%).

[0133] The synthetic route of compound DI-5 is as follows:

[0134]

[0135] Example 6

[0136] The structural formula of compound DI-6 is as follows:

[0137]

[0138] The synthesis steps of compound DI-6 are as follows:

[0139] Dissolve 3-bromophthalic anhydride (2.270 g) in the solvent acetic acid (30 mL), and then slowly add 3-trifluoromethyl-4-fluoroaniline (1.791 g) to form a mixed system. The imide reaction was carried out at 120 °C under reflux for 16 h. The reaction system was poured into deionized water for washing, extracted with dichloromethane, rotary evaporated and dried, purified by column chromatography, and dried at 130 °C under vacuum. 3-Bromophthalimide compound (3.36 g, yield 86.6%) was obtained;

[0140] And, a mixed system containing the 3-bromophthalimide compound (1.94 g), norbornadiene (0.23 g), cesium carbonate (3.30 g), triphenylphosphine (0.29 g), palladium acetate (0.057 g) and the solvent dioxane (48 mL) was reacted at 130 °C for 72 h. After the reaction was completed, the reaction system was washed with an aqueous sodium chloride solution, and then the organic phase was extracted with dichloromethane, rotary evaporated, dried, and recrystallized to obtain a diimide photoluminescent material containing a spin-forbidden system (1.22 g, yield 69.1%).

[0141] The synthetic route of compound DI-6 is as follows:

[0142]

[0143] Example 7

[0144] The structural formula of compound DI-7 is as follows:

[0145]

[0146] The synthesis steps of compound DI-7 are as follows:

[0147] Dissolve 3-bromophthalic anhydride (2.270 g) in the solvent acetic acid (20 mL), and then slowly add 4-methyl-3-fluoroaniline (1.252 g) to form a mixed system. Carry out the imide reaction at 130 °C under reflux for 20 h. Pour the reaction system into deionized water for washing, extract with dichloromethane, rotary evaporate to dryness, purify by column chromatography, and dry at 130 °C under vacuum. Obtain 3-bromophthalimide compound (3.04 g, yield 91.0%);

[0148] In addition, make a mixed system containing the 3-bromophthalimide compound (1.67 g), norbornadiene (0.23 g), cesium carbonate (3.55 g), triphenylphosphine (0.31 g), palladium acetate (0.062 g) and the solvent dioxane (50 mL) react at 140 °C for 68 h. After the reaction is completed, wash the reaction system with an aqueous sodium chloride solution, then extract the organic phase with dichloromethane, rotary evaporate, dry, and recrystallize to obtain a diimide photoluminescent material containing a spin-forbidden system (1.16 g, yield 77.5%).

[0149] The synthesis route of compound DI-7 is as follows:

[0150]

[0151] The characterization data of the diimide photoluminescent materials containing a spin-forbidden system prepared in Examples 1-7 are shown in Table 2.

[0152] Table 2 Performance data of the diimide photoluminescent materials containing a spin-forbidden system prepared in Examples 1-7

[0153]

[0154]

[0155] It can be seen from the test results in Table 2 that a diimide photoluminescent material containing a spin-forbidden system prepared by the present invention has the characteristics of triple emissions of room temperature phosphorescence, fluorescence, and delayed fluorescence; specifically, the fluorescence absorption peaks are at 444-461 nm and 529-551 nm, the delayed fluorescence is at 448-465 nm, the room temperature phosphorescence peak is at 537-555 nm, and the room temperature phosphorescence lifetime reaches 325-456 ms. It is a very good photoluminescent material with triple emissions of fluorescence, delayed fluorescence, and room temperature phosphorescence.

[0156] In addition, with reference to the foregoing embodiments, the inventors of this case also conducted tests using other raw materials, process operations, and process conditions described in this specification, and all obtained relatively ideal results.

[0157] It should be understood that the technical solutions of the present invention are not limited to the restrictions of the above specific implementation cases. Any technical deformation made according to the technical solutions of the present invention without departing from the purpose of the present invention and the scope protected by the claims falls within the protection scope of the present invention.

Claims

1. A diimide photoluminescent material containing a spin-forbidden system, characterized in that the diimide photoluminescent material has a structure shown in any one of Formula (I) - Formula (IV): wherein, R is independently selected from any one of the structures shown in the following formula: wherein, * is the connection point of the group.

2. A preparation method of the diimide photoluminescent material containing a spin-forbidden system according to Claim 1, characterized in that it includes: subjecting a first mixed reaction system containing a halogenated phthalic anhydride, an amine monomer and a first solvent to an imide reaction at 110°C to 120°C for 12 to 24 hours to obtain a halogenated phthalimide intermediate compound; and subjecting a second mixed system containing the halogenated phthalimide intermediate compound, norbornadiene, an inorganic base, a catalyst and a second solvent to a reaction at 130°C to 150°C for 72 - 120 hours to obtain a diimide photoluminescent material containing a spin-forbidden system.

3. The preparation method according to Claim 2, characterized in that: the halogenated phthalic anhydride is any one or a combination of two or more of bromophthalic anhydride, chlorophthalic anhydride, and iodophthalic anhydride.

4. The preparation method according to Claim 3, characterized in that: the halogenated phthalic anhydride is bromophthalic anhydride.

5. The preparation method according to Claim 2, characterized in that: the amine monomer is selected from any one of the structures shown in the following formula:

6. The preparation method according to Claim 2, characterized in that: the first solvent is any one or a combination of two or more of acetic acid, formic acid, and propionic acid.

7. The preparation method according to Claim 6, characterized in that: the first solvent is acetic acid.

8. The preparation method according to Claim 2, characterized in that: the inorganic base is any one or a combination of two or more of potassium carbonate, sodium carbonate, cesium carbonate, calcium carbonate, and magnesium carbonate.

9. The preparation method according to Claim 8, characterized in that: the inorganic base is cesium carbonate.

10. The preparation method according to Claim 2, characterized in that: the catalyst includes any one or a combination of two or more of palladium acetate, tris(dibenzylideneacetone)dipalladium, tetrakis(triphenylphosphine)palladium and triphenylphosphine.

11. The preparation method according to Claim 10, characterized in that: the catalyst includes palladium acetate and triphenylphosphine.

12. The preparation method according to Claim 2, characterized in that: the second solvent is toluene and / or dioxane.

13. The preparation method according to Claim 12, characterized in that: the second solvent is toluene.

14. The preparation method according to Claim 2, characterized in that: the molar ratio of the halogenated phthalic anhydride to the amine monomer is 1:1 to 1:1.

2.

15. The preparation method according to Claim 2, characterized in that: the mass ratio of the halogenated phthalic anhydride to the first solvent is 1:10 to 1:

20.

16. The preparation method according to Claim 2, characterized in that: the mass ratio of the halogenated phthalimide intermediate compound to the second solvent is 1:30 to 1:

50.

17. The preparation method according to Claim 2, characterized in that: The molar ratio of the halogenated phthalimide intermediate compound to norbornadiene is 2.2:1 to 2.1:

1.

18. According to the preparation method described in claim 2, it is characterized in that: The molar ratio of the norbornadiene to the inorganic base is 1:2 to 1:2.

2.

19. According to the preparation method described in claim 2, it is characterized in that: The ratio of the norbornadiene to the catalyst is 1:0.05:0.2 to 1:0.1:0.

4.

20. According to the preparation method described in claim 2, it is characterized in that: The reaction time of the imide reaction is 16 to 24 h.

21. According to the preparation method described in claim 2, it is characterized in that: The reaction temperature of the second mixed system is 130 °C to 150 °C.

22. According to the preparation method described in claim 2, it is characterized in that further comprising: After the imide reaction is completed, brine is added to the first mixed system for quenching, and then extraction, concentration, and purification are carried out to obtain the halogenated phthalimide intermediate compound.

23. According to the preparation method described in claim 2, it is characterized in that further comprising: After the second mixed reaction system is completed, brine is added for quenching, and then extraction, concentration, and purification are carried out to obtain the diimide photoluminescent material containing a spin-forbidden system.

24. Use of the diimide photoluminescent material containing a spin-forbidden system described in claim 1 in the preparation of anti-counterfeiting labels.

25. Use of the diimide photoluminescent material containing a spin-forbidden system described in claim 1 in organic photovoltaic optoelectronics.

26. An organic material having three emissions of fluorescence, delayed fluorescence, and room temperature phosphorescence, it is characterized in that at least comprising the diimide photoluminescent material containing a spin-forbidden system described in claim 1.

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